The More Earth-Like Planets = The Lesser the Probability of Intelligent Alien Life???

reply to post by H34T533K3R


Yes, I heard that.

8 billion is a very liberal estimate. The solar systems that have been looked at so far do not have Earth sized rocky planets as a general rule. But, it is early in the planet finding process, so time will eventually tell.

So, just a personal opinion: closer to 400 million Earth Sized rocky planets. Did you know that many stars are still too young to have fully developed planets? Places like Vega are barely 500 million years old, the Pleiades even younger. So when these guys say 8 billion in the HZ, you should think Earth ...only 2 and one is too close (Mars doesn't count...to small). Sol and his planetary plane should be considered average until other data contradicts it.

Cornell University says that there are 100 billion stars in the Milky Way. Most of these are "K" and "M" class. Except for very bright "K" class (K0, K1) stars, there is a rapidly decreasing probability of finding complex life, never mind "complex sentient".

Science and especially MSM likes to exaggerate things to make for better "stories". So, while the "actual count" may begin to approach 8 billion, those that could contain Human like life, or are even interesting, are far fewer. I'll stick with the 400 million...galaxy wide, and only about 10 local space-faring species.

Given the study only accounts for Earth-Like Planets orbiting similar stars to our Sun the number is likely to be far far higher when we take into account Earth-Like Planets orbiting Red dwarfs .

Since the number of stars is now known to be more bountiful, the number of planets orbiting red dwarfs is also elevated. This, of course, also raises the number of possible life-harboring planets there might be, van Dokkum added.

But enough exoplanet research has been done so far that a cautious prediction can be made that the odds are that the planet will orbit an M (red) dwarf star found in surveys taken within 100 light-years of Earth. Red dwarfs are much more numerous than sun-like stars, which exponentially increases the chances of being life favorable.

www.dailygalaxy.com...

Is there any intelligent life on Earth? That is the real question! I question the intelligence of any lifeform that kills each other and is damaging the ecosystem of its own home planet.

Even if we estimated that there are 900² billion earth like planets in the Universe, and we estimated that 10% of them are inhabited by intelligent beings (not likely), that represents a grain of sand in a 100 hectar field compared to the vastness of the Universe! In another words very hard to find, we haven't yet explored 1% of our own galaxy (and when I say explored I don't mean humans going out on spaceships of course). Add to that the fact that we have only just started "communicating". It's not at all surprising that we have not found intelligent life yet. We will not find intelligent life, intelligent life is more likely to find us, if not already done

www.setileague.org...

One such instrument (and there are only handful of them in the world) can see one part in a million of the sky. So if you happen to be looking on exactly the right frequency, at exactly the instant the Call comes in, there's still a 99.9999% chance you'll be pointing the wrong way.

Stopped reading when you said something about radio waves...

The frist radio signals were broadcast about 110 years ago...

This means that at 110 light-years away from earth — the edge of a radio ‘sphere’ which contains many star systems — our very first radio broadcasts are beginning to arrive. At 74 light-years away, television signals are being introduced. Star systems at a distance of 50 light-years are now entering the ‘Twilight Zone’.

However...

As radio signals leave earth, they propagate out in a wave form. Just like dropping a stone in a lake, the waves diffuse or “spread out” over distance thanks to the exponentially larger area they must encompass..... the strength of a radio signal will be only 1/4 as great once you are twice the distance from the source. At ten times the distance, the strength of the signal would only be one hundredth as great.

So...

..all of our terrestrial radio signals become indistinguishable from background noise at around a few light-years from earth

Source

Lets say that the nearest star to Earth has intelligent life... Proxima Centauri is about 4.2 some odd light years from Earth. IF they were broadcasting standard radio waves we probably wouldn't be able to detect them due to signal degredation.

I think your logic is flawed here.. more Earth-like planets increases the likely hood of intelligent life... not the inverse.

Yeah, it's that old argument. Somebody says that the galaxy/universe has all these various planets that could potentially evolve life on them that might be similar to our own. (Which, face it, is the only kind we're really interested in.) Oh, the galaxy is loaded with intelligent life! It's everywhere!

Okay, then why haven't we detected it? The more potential there is for life out there, the easier we should be able to see it, even with our limited abilities. So it's obviously not "everywhere."

But so far... nothing.

Which tends to suggest that our existence is very likely much more of a fluke than we realize, and there's even a relatively good chance that Earth is the only planet with life on it anywhere.

reply to post by Blue Shift


The problem is that the number that people consider as being " a s***load of planets", represents in reality next to nothing compared to the vastness of galaxies/Universe and the amount of planets in this space. It all comes down to a scale problem IMO.

Blarneystoner
Lets say that the nearest star to Earth has intelligent life... Proxima Centauri is about 4.2 some odd light years from Earth. IF they were broadcasting standard radio waves we probably wouldn't be able to detect them due to signal degredation.

If there are millions or billions of intelligent civilizations out there at various stages of development, then the odds are that some of them are or have been using better equipment than us. A decent percentage is going to be thousands or millions of years ahead of us technologically. The universe should be awash with signals riding radio or light or whatever, that we should be able to see. But it's suspiciously quiet.

If there was another civilization orbiting around Proxima Centauri, it's extremely unlikely that their technology would be at the same level as ours. If they were just 1,000 years ahead of us, that would greatly increase our chances of hearing them. But we don't hear or see anything coming from Proxima Centauri. We don't see or hear anything from anybody.

The more we should hear from aliens, the more suspicious it becomes when we don't.

WeSbO
The problem is that the number that people consider as being " a s***load of planets", represents in reality next to nothing compared to the vastness of galaxies/Universe and the amount of planets in this space. It all comes down to a scale problem IMO.

Sure, size is a problem. Distance is a problem. However, we have incredible amounts of time to balance things out. A planet 1,000 light years away is really, really far away. On the other hand, though, if they traveled in relatively slow space ships and it took them 10,000 years to get from there to here, we have that amount of time available. They've had billions of years to spread themselves around, or broadcast their signals. Plenty of time to get wherever they want to go.

But we don't see any of that. Looking up in the night sky, we don't massive artificial pyramid structures built from stars. We don't see stars winking at us in code. We don't see huge beams of coherent light stretching across the sky pointing the way. But there's no reason why we shouldn't, IF there were other intelligent beings out there. All of those things are possible. But they're not there.

reply to post by carewemust


God surely wasted her/his time, didnt she/he?

created more habitable exoplanets just for a genocidal race that could exterminate their own existence in just a day or two (by pressing a number of buttons) is waste of time -- and space

peace.

tanka418
reply to post by H34T533K3R

 

Yes, I heard that.

8 billion is a very liberal estimate. The solar systems that have been looked at so far do not have Earth sized rocky planets as a general rule. But, it is early in the planet finding process, so time will eventually tell.

So, just a personal opinion: closer to 400 million Earth Sized rocky planets. Did you know that many stars are still too young to have fully developed planets? Places like Vega are barely 500 million years old, the Pleiades even younger.

Good thing most of the Milky Way Galaxy is older than us..

The general rule is that our Sun and our solar system are on the young side.

Cornell University says that there are 100 billion stars in the Milky Way.

It's actually 200 billion.

Most of these are "K" and "M" class. Except for very bright "K" class (K0, K1) stars, there is a rapidly decreasing probability of finding complex life, never mind "complex sentient".

You misunderstand this.

The majority of the stars indeed are G through M. These are exactly the types of stars we expect to find complex, and perhaps even complex sentient life around.

On the lower end of the mass/temperature scale M-dwarfs live much longer than our Sun and many are already far older (8 billion years compared to our sun). Next up from them are K stars. The most likely places for advanced life because again, they live longer than G stars like our sun and many are already older than our Sun.

If the majority of stars were hotter and more short lived than our sun then that would be a problem. The fact that the majority are about the same or cooler/older than our sun is more encouraging for life, complex life and perhaps even intelligent complex life.

Science and especially MSM likes to exaggerate things to make for better "stories".

While you may be right about the mainstream media, you are dead wrong about science here. If anything, as a rule it DOWNPLAYS stuff like this until fairly sure.


I can tell you, as someone who knows quite a bit about this subject, as it is my field of study, there is far more that we still do not know about these planets however we do know that terrestrial planets are now the rule, not the exception.

That was what the Kepler telescope was designed to find out: How common Earthlike planets were.

That is what it did. And that is what was announced on Monday. It's that simple.

Had it not done that you would be bitching about wasted tax money.



Note how that slide urges CAUTION..... This is the rule in science. When you find something amazing the first question you ask is whether it is real.

They've looked at the data every which way, identifying errors, compensating for observational bias, etc before coming forward and saying anything definitive on Monday.

So, while the "actual count" may begin to approach 8 billion, those that could contain Human like life, or are even interesting, are far fewer. I'll stick with the 400 million...galaxy wide, and only about 10 local space-faring species.

And that would be a guess, perhaps as good as any other until we know more about these planets. I would never make any such pronouncement.

Even if 1% of that 8 billion developed intelligent life, that's still 80 million intelligent species. Or about 6.2 per a 100 light year spherical volume.

I will say this though, don't be surprised.

If nothing else, studying exoplanets has shown us some surprising things that contradict what we thought we knew about planetary formation. It could very well be that life, even complex life is more widespread than we thought.

By the way, that's been the general trend. It has been the trend since Copernicus.

Planets were once thought rare.

Then when the first planets around other stars were found to be Hot Jupiters some thought terrestrial planets might be rare around Sunlike stars (having been ejected, etc)

Then terrestrial planets were thought common but habitable zone terrestrials were thought rare.

Now on Monday we learned that, no, habitable terrestrial planets may be a lot more common than even Carl Sagan (ever the optimist) had suggested.

Contrary to your view, these people work damn hard squeezing every ounce of information out of data and their credibility depends on NOT making big, bold statements with out big bold evidence (which I have been watching on the live stream of the Kepler Science Conference since it begun Monday morning. Can you say the same?)

They do not go to conventions, sitting around making up juicy stories for tabloid media.

That said...

There are projects, and proposed projects which can and could tell us a lot more about these planets down to mapping their continents and oceans to detecting their waste energy, to imaging the lights of their cities if they have them.

All of which is technically possible but would require a LOT more money than we're spending on this stuff so far.

Kepler cost a total of $600 million.

Compare that to $2 billion dollars each B-2 stealth bomber or space shuttle cost, or the $2 billion the Hubble Space Telescope cost, or the nearly $9 billion its successor, the JWST cost.

All of which is miniscule compared to the $487 billion per year spent on a war in Iraq.


Want to find REAL ALIENS? Then make sure your nation's space science budget remains intact or is increased.

The money is there. The political will to use it to perhaps find out once and for all that we a) aren't that special, b) aren't alone and c) aren't the smartest things in the universe however is not.

Blue Shift
Yeah, it's that old argument. Somebody says that the galaxy/universe has all these various planets that could potentially evolve life on them that might be similar to our own. (Which, face it, is the only kind we're really interested in.) Oh, the galaxy is loaded with intelligent life! It's everywhere!

Okay, then why haven't we detected it?

Because we've only just begun to find ways to look for it and the Galaxy is a big place...

We have not looked specifically for artificial structures and emissions at all times, at all wavelengths.

What we've done is go to the beach and dip a bucket in the ocean.

You have decided that because that bucket has no fish in it then there must be few if any fish in the ocean.


Need I remind you:

JadeStar; Supposing that such a thing as a warp drive is possible, has any thought been given to detecting the sort of energy emissions these would be expected to give off ? I'm thinking of interstellar particles being pushed along in the wake of warped space. I wondering what sort of energy signature would be produced. What should we look for ?

Ross 54
JadeStar; Supposing that such a thing as a warp drive is possible, has any thought been given to detecting the sort of energy emissions these would be expected to give off ?

A little bit. There have been a few academic papers on how to say, detect an artificially constructed wormhole:
"On a macroscopic traversable spacewarp in practice" - arxiv.org...
"Astrophysics of Wormholes" - arxiv.org...


BTW: The Kardashev who co-authored the 2nd paper is the same guy who created the Kardashev scale for extraterrestrial civilizations which Michio Kaku often references. (Type 1, Type 2, Type 3, etc)


Here are a couple of articles about detecting warps or wormholes:
www.centauri-dreams.org...
crowlspace.com...


Perhaps the best way to detect a warping ship would be to detect gravitational waves. Unfortunately the satellite which might have been capable of this: LISA (Laser Interferometer Space Antenna)- got its funding cut.
en.wikipedia.org...

I'm thinking of interstellar particles being pushed along in the wake of warped space. I wondering what sort of energy signature would be produced. What should we look for ?

Well from the 1994 paper titled “Natural Wormholes as Gravitational Lenses.” a ship using one to travel would create the following signature: "an odd but identifiable form of lensing — two spikes of light with a dip in the middle."

Here is that paper: "Natural Wormholes as Gravitational Lenses" - arxiv.org...

It should be noted there are independent researchers going through Kepler data (their false positive and eclipsing binary databases) looking for such a signature that could not be explained as a natural object: ie: eclipsing binary star, error in data or CCD malfunction.

There has also been a paper on using microlensing surveys to look for wormholes: "Search for exotic matter from gravitational microlensing observations of stars" - arxiv.org...


So yeah, there are a lot of people in these fields "thinking outside of the box" looking for stuff we see in sci-fi. They don't go to UFO conventions proclaiming they found it though

There are still way too many variables to be sure.

As a matter of timing the universe could be teeming with life that just never seems to intersect- the last radio signal from an advancing civilization always beaming unnoticed through their nearest neighbors as those neighbors are inventing the wheel, the more advanced civilization dying out just as their neighbors send their first radio signals, and the more advanced neighbors first space probe crashing into the ruins of the neighbors futuristic civilization 500 years after they have died out.

And it goes a lot further than that- how normal are we and our technology? Maybe our success with electromagnetism is quaint or incredibly clever by galactic standards- maybe nobody else ever managed to settle enough of their planet to need radio communications before coming up with something better than radio, or maybe everybody else had the unified field theory beaten within a year of discovering magnetism.

We could even be under quarantine. Maybe there is no cosmic background radiation- maybe for thousands of years alien sports scores were coming in clear as day with nobody listening, then somebody noticed us developing, dropped in to take a look, saw that it was an unnervingly clever species of pack-hunting killer ape, and decided it would be best to just scramble everything coming our way into random noise and hope we never came out to take a closer look.

Perhaps sentient, intelligent races choose to leave this universe or dimension when they evolve far enough to be able to choose to do so.

Maybe there's some sort of technical ascension into a higher plane of existence that becomes possible once you've been around long enough as a species and your technology and knowledge has evolved far enough.

Maybe we're the lonely late comers. The dunces or green horns who haven't discovered how to build transcendence drives or hyperdrives.

Or maybe all life sufficiently intelligent to be able to communicate over interstellar distances using radio waves is doomed to technological self-annihilation.

reply to post by carewemust


I don't fully support the radio silence evidence as a lack of extra terrestrial life, and to a degree accept that it does impact on technological developed culture but there are so many possible paths that radio broadcasting really does not prove anything and then there is also interference from the medium that may affect radio communications (to be sure we need to place a receiver in the next star system to experimentally verify that it works, our guesstimate is based on radio emissions from star like objects that we only think we understand, we may be completely off)...

PS: Even technological superior has a very high leeway, even us have been radically shifting our use of radio waves in the last ~100+ years. Now imagine that they stabilize their society at a stage before radio, we have cultures that do just that amongst ourselves...

DaRAGE
reply to post by carewemust

 

Lets just say 100 billion galaxies (a nice round number)
and lets assume that 8 billion in each galaxy had earth like planets.
So that's 800 Billion earth like planets.

Thats just 100billion times 8, instead of 8 billion.


8 billion earth-like planets in each of the 100 billion galaxies?

8 billion (8 x 10^9) TIMES 100 billion (100 x 10^9)?

(8 x 10^9) TIMES (100 x 10^9) "in scientific notation"
8 x 100 = 800 "Multiply the coefficients"
9 + 9 = 18 "Add the base 10 exponents"
800 x 10^18

so it would be 800 Quintillion or 800,000,000,000,000,000,000 earth like planets

So with this new number,
if 0.0001% of them had life like earth
(800 x 10^18) TIMES (1 x 10^-4)
(800 x 10^14) or (80 x 10^15) or 80 Quadrillion

adding a few more zeros (0.000001%)
80 Trillion

The scrambling of electromagnetic signals wouldn't even have be be on our account. As such signals become more efficient; more tightly beamed, and digitized, the more easily they can appear to the uninitiated as pure noise.
Communications theory finds that the most efficient signal is virtually indistinguishable from noise, without the proper decoding protocol.
These signal would also presumably be sent through bulk space, making a detour around normal space, achieving an effective speed well beyond that of light.

reply to post by JadeStar

You misunderstand this.

The majority of the stars indeed are G through M. These are exactly the types of stars we expect to find complex, and perhaps even complex sentient life around.

On the lower end of the mass/temperature scale M-dwarfs live much longer than our Sun and many are already far older (8 billion years compared to our sun). Next up from them are K stars. The most likely places for advanced life because again, they live longer than G stars like our sun and many are already older than our Sun.

If the majority of stars were hotter and more short lived than our sun then that would be a problem. The fact that the majority are about the same or cooler/older than our sun is more encouraging for life, complex life and perhaps even intelligent complex life.

No, actually I do understand; I have a different opinion.

It is my opinion that "M" and colder "K" class stars will not have natural evolving complex sentient life, and IF one is found, that species, unless very old, will not be space faring.

Contrast this with "G" and "F" class which, again in my opinion, are better suited to complex, sentient, space faring life forms.

I have reasons for my opinions, but, they are not scientifically acceptable.

Science is going to find, and actually seem to be, that planets are ubiquitous and life is as well.